Synchro-mesh devices are commonly used in vehicle gear boxes to simplify the operation of gear change so that this can be done by unskilled drivers without the occurrence of clashes and consequent damage. These devices usually incorporate a positive engagement clutch such as a dog clutch and a friction clutch such as a cone clutch. These clutches were designed primarily for torque-interrupt shifting where the power was momentarily cut off during gear change. The gear and shaft were first brought to the same speed by the friction clutch and then a positive engagement was made through actuating the positive engagement clutch. The synchro-mesh devices can be applied to sliding-mesh gear boxes but almost always used with constant-mesh boxes. In spite of their popularity, the synchro-mesh devices are not always trouble free. There are times when the jaws or teeth of one member of the positive engagement clutch are not aligned up well with the groove on the mating member and the clutch will not engage. In addition, synchro-mesh devices are prone to wear and are not suitable for power-shifting.
With the introduction of automated manual transmissions (AMT), the desire for trouble free engagement and power-shifting becomes increasingly strong. It almost becomes a necessity rather than a luxury. The present invention provides a compact gear selector, capable of providing positive and trouble free engagement and power-shifting operation.
European patent application EP 0 524 691 A1 discloses a mechanical transmission for toy automobiles. The transmission has gears for selecting different transmission ratios fitted onto a cylindrical element. In side the cylindrical element, an number of keys engage with an equal number of seats transmit movement between the gears at a different ratio between the input and output of the transmission.
European patent application EP 0 508 967 A1 discloses a gear shifting mechanism of the desmodromic type for providing a change gear with a command shaft equipped with desmodromic meshes. The mechanism includes a keying means having a plurality of grooves that couple with a corresponding plurality of pivots.
Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.